Fuel ethanol production depends solely on grain to provide raw materials, which can no longer meet the demand for fuel ethanol production. China needs to take a diversified supply path. In the future, the development of fuel ethanol in China should rely more on non-food materials.
Taking into account China's food security issues, from 2006 to date, on the basis of ensuring existing production of grain ethanol, the development of fuel ethanol production enterprises in China is mainly in two directions: one is cassava ethanol; the other is cellulose ethanol. Both of them belong to non-food crops, among which, cassava ethanol is already in the stage of large-scale production, and its technological development has been relatively complete. Cellulosic ethanol is still in the experimental stage in China and the technology needs to be improved.
Cassava is the best alternative to corn
Foreign research institutes have compared the yield of certain alcoholic fermentations produced by some crops. In several major alcoholic raw materials crops, the alcohol yield per unit area of ​​land is the highest in cassava, followed by sugar cane.
Cassava is an ideal substitute for the production of alcohol instead of corn and other raw materials. The development of cassava alcohol resources is promising. In the same land and resources, planting cassava can produce nearly 2 times more alcohol than corn. Using cassava for alcohol production, the entire crop has no waste and is highly efficient.
The ratio of fixed assets investment to sales income of large cassava alcohol plants is 1:5, the construction period is short, delivery is small, investment recovery is fast, and benefits are high. In addition, the idle equipment for the production of alcohol from existing sugar factories using molasses can be used for cassava alcohol processing.
In terms of variable costs, raw material costs for producing fuel ethanol from corn have remained high due to rising food prices. According to the industry average, one ton of fuel ethanol can be produced per 3.3 tons of corn. Based on the market average prices from January to June of 2007, the market for corn is 1,500 to 1,700 yuan per ton, plus processing fees of around 800 yuan, dehydration costs of 100 yuan, and sales costs of 100 yuan per ton of fuel ethanol. The cost is about 5950~6610 yuan. When selling to an oil company, the price per ton of fuel ethanol is about 4,500 yuan, and the value of the alcoholic protein feed produced during the production process is about 960 yuan. This way, if there is no subsidy, the company will lose 490 yuan per ton of corn ethanol. ~1150 yuan or so.
Compared with corn ethanol, the cost per ton of cassava ethanol is 1800~2460 yuan lower, and the price per ton of cassava ethanol is calculated based on the sales price of 4,500 yuan/ton, plus the by-products produced in the production process, in the absence of subsidies, each Tons of cassava ethanol can make a profit of 1070 yuan/ton. This does not include the possibility of obtaining CDM (Clean Development Mechanism) project funding each year due to the reduction of carbon dioxide emissions.
The core content of the CDM project is to allow developed countries to use funds and technologies to cooperate with developing countries and implement development and utilization of biomass in developing countries so as to achieve the goal of reducing greenhouse gas emissions. Each ton of fuel ethanol can generate 2 tons of carbon dioxide emission reductions, according to the current average price of the international market, emission reductions of about 10 US dollars / ton, per ton of fuel ethanol emission reduction benefits of 20 US dollars / ton. Then, according to the ethanol sales price of 4,500 yuan / ton, cassava 450 yuan / ton, alcohol protein feed 1200 yuan / ton, the annual production of 100,000 tons of cassava ethanol gross profit of 107 million, in addition to CDM project funding can also be 15 million yuan.
Cellulose ethanol has the greatest development potential
In the long term, cassava is just a transitional raw material for fuel ethanol production in China, and it is not enough to change the entire energy structure of China. It is the plant fiber represented by straw that bears the heavy responsibility for changing China's energy structure. The development of industrial technologies for the large-scale production of lignocellulosic biomass fuel ethanol is a fundamental solution to the high cost of raw materials for fuel ethanol and limited raw materials.
According to the data provided by the Ministry of Agriculture, China's straw resources amount to 600 million tons. At present, 300 million tons are used for fuel wood fuel consumption, and the rest are burned. According to the data provided by the Ministry of Forestry, China's forestry waste resources amount to 800 million tons, including 500 million tons of industrial consumption, and 300 million tons are urgently needed for development and utilization. According to the U.S.'s technical level of producing 1 ton of ethanol per 4 tons of straw, these raw materials will produce 150 million tons of fuel ethanol. If the cellulose fuel ethanol technology achieves breakthrough progress and industrial production is achieved, it will play a crucial role in breaking through the bottleneck of China's resources.
In August 2006, Henan Tianguan Group started to build a cellulose ethanol project with an annual output of 3,000 tons. This is the first domestic production line for cellulosic ethanol. The construction and putting into use of this production line will make the use of crop straw fiber raw materials to produce ethanol, and its significance is very far-reaching. Due to the scale constraints, the production cost of fiber ethanol is as high as 6000 to 6500 yuan/ton, which is 500 to 1,000 yuan more than the cost of wheat as raw material to produce fuel ethanol. However, as the test is successful, the cost is expected to decrease after the production capacity is expanded.
In terms of cellulosic ethanol, COFCO Biochemical Energy Division also made specific plans. In April 2006, COFCO initiated the construction of a 500-ton/year cellulose ethanol test facility in Heilongjiang. The design was completed in June and the construction was completed in September. The successful commissioning in October was completed. From the experimental results, various technical indicators have reached the international advanced level. The pre-processing section of the project, using continuous steam explosion equipment, is the first device in the world to use continuous steam explosion technology for cellulosic ethanol production. The enzyme preparation was jointly developed by COFCO and Denmark Novozymes. In the next step, COFCO will step up the development of a 10,000-ton demonstration plant process package based on the further optimization and improvement of the pilot test to lay the foundation for the demonstration of the cellulose alcohol industry. COFCO and Danish Novozymes, a company with world-leading technology, have established a partnership and will achieve large-scale production of cellulosic ethanol within 2-3 years.