What Is the Corn Industry?

The deep processing of corn is a concrete manifestation of optimizing the industrial structure, extending the industrial chain, and increasing the added value of products. It is also an important measure to solve the problems of agriculture, rural areas and farmers. For example, bio-alcohol can be refined. Use corn as alcohol to solve energy problems. Another example: corn germ meal, alcohol germ meal feed, corn husk spraying, corn husk, corn gluten meal, bran and so on.

Corn processing equipment

Take the United States, the world s largest corn production and deep processing volume, as an example. There are more than 3,000 corn products developed. The consumption of deep processing corn increased from 48.107 million tons in 1999 to 63.264 million tons in 2003, an average annual increase of 7.5% Per capita consumption of corn reached 88 kg.

Although China's corn processing industry started late, from a few hundred thousand tons of consumption in the 1980s to a rapid increase of 10% per year in the 1990s, hundreds of products have been developed. Industrial consumption reached 11 million tons in 2005. The proportion of total corn consumption also increased from 0.5% to 13.4%. Although there are many corn deep-processing products, they are mainly concentrated in related fields such as ethanol, starch and chemical alcohol.

Corn is one of the most important foods in the world. The nutritional content of corn is better than rice, potatoes, etc. The disadvantages are large particles, poor taste and low stickiness. With the development of corn processing industry, the edible quality of corn has been continuously improved. Formed a variety of corn foods. Corn can have the following processing methods to make it a new thing and increase the value of corn.
(1) Specially made corn meal and germ meal: Corn grains have a high fat content, and produce a bad taste due to fat oxidation during storage. After processing, the special corn flour can reduce the oil content to less than 1%, which can improve the edible quality and fine particle size. Suitable for blending with wheat flour for various pasta. Because it is rich in protein and more vitamins, the added food has high nutritional value and is a good food for children and the elderly.
(2) Puffed food: Corn puffed food is a convenient food that has risen and flourished since the 1970s. It has the characteristics of looseness, porosity, uniform structure and soft texture. rate.
(3) Corn flakes: It is a fast food, easy to carry, and has a long storage time. It can be eaten directly or made other foods. It can also be made into various flavors of convenience foods with different condiments, water, milk, soup Brew and serve.
(4) Sweet corn: It can be used as vegetables or fresh food. Processed products include whole ear quick freezing, quick grain freezing, and canning.
(5) Corn beer: Because the protein content of corn is close to that of rice and lower than barley, and the content of starch is close to that of rice and higher than barley, it is an ideal raw material for beer production.

From ancient times to modern times, no matter whether you are an emperor or an ordinary citizen, there are many people who like to eat some corn foods. For this reason, the ancestors have developed many kinds of corn eating methods, leaving us a valuable dietary heritage. Nutritionists agree that corn has the highest nutritional value and health benefits of all human staple foods. Let us analyze the significance of deep processing of corn.
Corn contains 5-10 times more vitamins than rice and wheat. Corn, also known as bud valley, corncob, corn. Corn contains a large number of nutritional and health substances, in addition to carbohydrates, proteins, fats, carotene, and riboflavin.
The experts compared the nutritional value and health effects of various staple foods such as corn, rice, and wheat, and found that the vitamin content in corn is very high, which is 5-10 times that of rice and wheat. The nutritional value is higher than ordinary corn. Sweet corn has 1-2 times higher protein, vegetable oil and vitamin content than ordinary corn, and "life element" selenium content is 8-10 times higher. Of the 17 amino acids contained, 13 are higher than ordinary corn.
Corn deep processing believes that from a health perspective, people consuming corn oil have far greater benefits than edible peanut oil and other vegetable oils. The coarsely ground cornmeal contains a large amount of leucine and glutathione, which can inhibit the side effects of anticancer drugs on the human body, and also inhibit tumor growth. Because glutathione can lock the growth of carcinogens like a yoke, making it non-toxic and eventually excreting it. ^[1]

Heilongjiang

In order to promote the reform of the corn storage and storage system and promote the healthy development of the corn deep processing industry in Heilongjiang Province, the provincial government decided to increase the province's 2015 product sales income to 20 million yuan or more or to have an annual processing capacity of 100,000 tons and more to produce starch or alcohol. The corn deep-processing enterprises of the product purchased and entered the warehouse from November 1, 2016 to April 30, 2017, and processed and consumed the newly-produced corn in 2016 in the province before June 30, giving a subsidy of 300 yuan per ton (standard moisture ). ^[3]

Water quality characteristics of corn deep processing wastewater

The production wastewater of the corn deep-processing comprehensive utilization technology transformation project mainly includes sewage condensate, equipment washing wastewater, workshop washing water, domestic sewage, boiler wastewater and cooling system drainage. Boiler wastewater and cooling system drainage can be directly discharged without treatment. After treatment, the wastewater needs to meet the Grade I standard for comprehensive wastewater discharge standards (GB8978-1996).

While the drainage of the corn deep processing industry highlights the commonality of the industry, due to its diversity of production and words, the composition of wastewater is more complex, and the pollution degree varies greatly due to different products. For example, the pollution degree of alcohol wastewater is higher than other products. And the C / N ratio is unbalanced; the pollution degree of the evaporative condensate in the production process is relatively low; the temperature of the drainage water is relatively high, and most of them need to be cooled.

Process Design of Corn Deep Processing

Sewage treatment process flow is: comprehensive wastewater-grille-conditioning tank-UASB-sedimentation tank-CASS-coagulation sedimentation tank-water. The integrated wastewater is transported from the production workshop to the sewage treatment station through pipes, and part of the suspended solids in the wastewater is removed through the grille. It flows into the adjustment tank to homogenize the water quality and volume, and removes larger suspended solids in the sewage. In order to prevent the suspended matter in the water from settling in the regulation tank and affecting the normal operation of the regulation tank, a pre-aeration system is set in the regulation tank, and pre-aeration treatment is performed on it regularly.

The adjusted sewage enters the UASB system through the submersible sewage pump. Through the biological metabolism of anaerobic sludge, most of the organic pollutants in the sewage are degraded. After the UASB reactor is treated, the sewage flows into the vertical sedimentation tank to separate and remove the suspension in the water. Sewage sludge and a small amount of organic pollutants, the sewage flows into the CASS reaction tank for aerobic biological treatment after sedimentation. Under the action of aerobic sludge, most of the remaining organic pollutants in the water are degraded and removed. Condensate sedimentation tank (secondary sedimentation tank), treated by coagulation sedimentation. Remove suspended organic pollutants in water, and discharge water after coagulation and sedimentation.

Corn deep processing test steps

Corn deep processing wastewater treatment project consists of pretreatment system, physical and chemical treatment system, anaerobic treatment system and aerobic treatment system.

1. The pretreatment system includes grille wells and conditioning tanks to remove large floating objects and homogenize water quality. There is a pre-aeration pipeline system in the adjustment tank. The blower is used to pass in compressed air to fully mix the sewage, and the soluble dyes in the wastewater are oxidized to insoluble substances again to ensure the continuous normal operation of the subsequent treatment system.

2. Anaerobic treatment Anaerobic treatment of high-concentration organic wastewater has the advantages of high equipment load, low nutrient requirements, low residual sludge production, no aeration required, low operating costs, and energy recovery. It is the most commonly used method for treating high-concentration organic wastewater. One of the methods. In the treatment of high COD wastewater such as yeast wastewater, the effect of anaerobic treatment determines the success of the entire biochemical treatment. With the development of biomass, load-resistance and toxicity-resistant high-efficiency reactors. It makes the anaerobic treatment difficult to degrade and high-concentration wastewater more and more widely used. Adding different packing layers between the UASB sludge bed layer and the three-phase separator has the characteristics of collecting suspended sludge by using an anaerobic biological filter bed, improving the quality of the effluent water, and improving the suspended sludge bed layer of the traditional UASB reactor. The problem of low treatment efficiency effectively reduces the inhibitory effect of ammonia nitrogen and sulfate, and achieves better results. No blockage occurred. Low UASB ascending flow rate. Residual yeast cells accumulate in the sludge bed, which has the risks of replacing anaerobic sludge and the sensitivity of UASB to pollution load. The internal circulation anaerobic reactor has been applied in yeast wastewater treatment, and the COD removal efficiency is about 80%.

3. The aerobic biochemical treatment system uses a two-stage aerobic method. The first stage adopts activated sludge aeration tank, the middle sink tank is a vertical flow sedimentation tank, and the sludge in the middle sink tank is returned to the hydrolysis and acidification tank; the second stage uses biological contact oxidation tank, and the second sedimentation tank uses vertical flow sedimentation. Pool. In this way, different attribute bacteria can be relatively cultivated, which is beneficial to improve the processing efficiency, and can shorten the aeration time and save the aeration amount compared with the non-stage aeration tank. And the second stage adopts contact oxidation method, which can improve the processing efficiency, reduce the land occupation and save energy consumption. There is a quick filter behind the second settling tank, which is mainly used to remove suspended matter (mainly the shed biological bacteria film) from the effluent of the second settling tank. It is expected that the indicators of the secondary effluent will reach the standard, so it can usually be discharged directly without passing through the fast filter.

Conclusion of Corn Deep Processing Test

From the perspective of wastewater quality, COD concentration is high, acidic, and easy to acidify and deteriorate. At the same time, in order to prevent the suspended matter in the water from settling in the regulation tank and affecting the normal operation of the regulation tank, a pre-aeration system is set in the regulation tank, and pre-aeration treatment is performed on it regularly. The UASB anaerobic reactor can effectively increase the sludge loading rate. The hydraulic retention time of wastewater in the reactor is short, so the required tank capacity is greatly reduced, the equipment is simple, and the operation is convenient. There is no need to set up a sedimentation tank and a sludge return device. There is no need to fill the filler, and there is no need to set up a mechanical stirring device in the reaction zone. The cost is relatively low, it is easy to manage, and there is no clogging problem. The aerobic treatment uses the CASS process, which effectively suppresses sludge swelling. When the wastewater flow rate is lower than the designed value, the CASS system can adjust the setting value of the level gauge, use part of the volume of the reaction cell, or adjust the reaction time, thereby avoiding unnecessary power consumption. The CASS purification process is controlled automatically, with low labor intensity and greatly reduced processing costs.

It takes a long time for the sludge bed of the UASB reactor to reach stability. Too high and too fast water inlet load can easily cause system shock, sludge loss and system shock; the water inlet load cannot keep up with the rapid growth of sludge and Breeding, so the start-up time should be extended. In the actual operation process, due to the influence of the off-season and peak seasons, the water quality and quantity have changed greatly. Therefore, the operating conditions of each treatment structure should be adjusted according to the actual situation, so that the effluent finally reaches the discharge standard. Increasing pre-aeration can effectively prevent the control pool from emitting odor in summer. When the temperature is low in winter, the aeration volume of the CASS tank can be increased to strengthen the biological effect and ensure the treatment effect.

In the design of wastewater treatment, it should be taken into account that the corn deep processing industry has a long industrial chain, the product composition is more complex, and the drainage water quality of different products has different characteristics, and a targeted treatment plan should be formulated. For example, the corn starch device evaporates the condensate. Because of its high temperature, the water must pass through the cooling tower before entering the subsequent treatment device. For the higher starch content in starch wastewater, the coagulation reaction is used to enter the inclined plate to precipitate. The device is reused after dewatering by plate and frame filter press. On the top of the conditioning tank, pre-acidification tank, and biological reactor, odor is easily emitted, which contains a small amount of reducing acid sulfur compounds. In order to control the pollution of these gases, these exhaust gases are introduced into the scrubber tower through a pipe collection system by a induced draft fan, and the odorous substances in the exhaust gas are absorbed by the lye spray at the top of the scrubber tower to deodorize them. ^[5-7]