Cellulosic plants, bioethanol

Much current research focuses on the formation of bioethanol from cellulosic plants, plants that contain the complex carbohydrate cellulose. Cellulose is not readily metabolized and so does not compete with the food supply. However, the chemistry for converting cellulose to ethanol is much more complex than that for converting corn. Cellulosic bioethanol could be produced from very fast-growing nonfood plants, such as prairie grasses and switchgrass, which readily renew themselves without the use of fertilizers. 

BP has investments in an ethanol plant with DuPont and Associated British Foods. It is also investing in cellulosic ethanol research and developing jatropha as a biodiesel feedstock. BP and DuPont are planning a biobutanol demonstration plant and BP would like to eventually convert their ethanol plant to biobutanol production. BP has a 400 million investment with Associated British Foods and DuPont to build a bioethanol plant in the U.K. that may be converted to biobutanol. It has spent 500 million over 10 years at the Energy Biosciences Institute in California to research future biofuels and 9.4 million over 10 years to fund the Energy and Resources Institute (TERI) in India to study the production of biodiesel from Jatropha curcas. It also has a 160 million joint venture with D1 Oils to develop the planting of Jatropha curcas. 

Outside of the use of cellulose for papermaking, starch is the most widely used plant-derived carbohydrate for non-food uses. Around 60 million tonnes of raw starch are produced per year for food and non-food uses. The US accounts for most of the world s production, utilising starch from maize, which accounts for over 80% of world production. The starch market in the US is driven by the large isoglucose sweetener market and now increasingly by the growing bioethanol market, which uses maize as a fermentation feedstock. Europe derives most of its starch from wheat and potatoes, which account for 8% and 5% of world starch production, respectively. The other main source of starch is cassava (tapioca), produced in South East Asia. Small amounts of oat, barley and rice are also exploited for starch production. Many edible beans are also rich in starches, but are not commonly exploited for non-food uses. 

Using the advanced bioethanol technology available, it is possible to produce ethanol from any cellulose/hemicellulose material, which means any plant or plant-derived material. Many of these materials are not just underutilized and inexpensive, but also create disposal problems. For example, rice straw and wheat straw are often burned in the field, a practice that is becoming limited by air pollution concerns. Also, much of the material now going into landfills is cellulose/hemicellulose material and could be used... 

In the last decade, increasing efforts have been dedicated worldwide to realizing the implementation of biorefinery plants for the eonversion of lignocellulosic and cellulosic waste to starting materials for the biotechnological production of bioethanol, biopolymers and a range of fine chemicals. Whereas the material recovery from the lignin fraction is limited to the production of adhesives, sulphur-free fuels and some aromatics, cellulose and hemicellulose provide a rich source of... 

Sugar beet presents low-water, low-quality soil requirements, and less fertilizer than other sugar crops. Residues from sugar beet-based ethanol production, pulp and bagasse, may be used for the production of cellulosic ethanol. A European demonstration plant in Fresno County (Califomia, US) operates with whole beet as feedstock, delivering 75 million liters of bioethanol per year, accounting for a 71 % saving in CO2 emissions (Platform, 2015). 

As an example for the industrial application of waste valorization, the enterprise Enerkem opened in Canada a 5-miUion-liter-capacity demonstration bioethanol and biochemical plant in 2012 based on wood. The same company finished in 2015 the constmction of a larger plant (30 million liter) in Edmonton, Alberta, for the production of lignocellulosic ethanol from municipal solid waste. Despite this, production is nowadays focused on methanol, carbon dioxide, and other chemicals that present higher revenues than ethanol due to their lower market prices (Dessureault, 2015). Future plants for the production of cellulosic ethanol from nonrecyclable wastes have also been announced in Quebec, while other Canadian cities will produced clean bio-based heat and power through gasification, pyrolytic bio-oil, etc. 

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