A growing world population coupled with changing diet is projected to increase demand for food production by 70% by 2050. Helping farmers lose less of their crops will be a key factor in promoting food security. In ad...A growing world population coupled with changing diet is projected to increase demand for food production by 70% by 2050. Helping farmers lose less of their crops will be a key factor in promoting food security. In addition to pesticides GM crops will continue to be a vital tool in the diverse range of technologies that can maintain and improve living standards for the people of the world. The EU is dependent for 65% on imports of protein-rich feedstuffs for which there are no substitutes in the short term. The EU livestock sector uses imported soybean, soybean meal and maize by-products as animal feed. Without an adequate supply of these feed ingredients, the EU’s livestock production will loose competitiveness. However, demands from the EU differ to those from third countries with respect to the GM varieties grown, and what are authorised for import into the EU. The risk that supplies of soya products and maize by-products could be affected by the low-level presence of non-EU approved GM material has not been fully resolved as the EU has allowed just a 0.1% tolerance for this plus 0.05% tolerance for measuring uncertainty. This could cause supply problems for the animal feed industry, and ultimately supply of food to consumers. The importance of the EU market and EU requirements for the major soybean and maize exporter countries is declining over time and it is becoming increasingly difficult and costly to maintain a non-GM supply chain in the EU. Food companies and supermarkets will struggle to stay GM-free. EU member states dependent on imports will be forced to deal with more GM presence in their chain. Market forces are forcing governments to authorize products more efficiently, develop tolerance policies or tolerate unapproved varieties in their imports.展开更多
This paper proposes optimization models of crude oil distillation column for both limited and unlimited feed stock and market value of known products prices. The feed to the crude distillation column was assumed to be...This paper proposes optimization models of crude oil distillation column for both limited and unlimited feed stock and market value of known products prices. The feed to the crude distillation column was assumed to be crude oil containing naphtha gas, kerosene, petrol and diesel as the light-light key, light key, heavy key and heavy-heavy key respectively. The models determined maximum concentrations of heavy key in the distillate and light key in the bottom for limited feed stock and market condition. Both were impurities in their respective positions of the column. The limiting constraints were sales specification concentration of light key in the distillate [ ], heavy key in the bottom [ ] and an operating loading constraint of flooding above the feed tray. For unlimited feed stock and market condition, the optimization models determined the optimum separation [ and ] and feed flow rate that would give maximum profit with minimum purity sales specification constraints of light key in the distillate and heavy key in the bottom as stated above. The feed loading was limited by the reboiler capacity. However, there is need to simulate the optimization models for an existing crude oil distillation column of a refinery in order to validate the models.展开更多
文摘A growing world population coupled with changing diet is projected to increase demand for food production by 70% by 2050. Helping farmers lose less of their crops will be a key factor in promoting food security. In addition to pesticides GM crops will continue to be a vital tool in the diverse range of technologies that can maintain and improve living standards for the people of the world. The EU is dependent for 65% on imports of protein-rich feedstuffs for which there are no substitutes in the short term. The EU livestock sector uses imported soybean, soybean meal and maize by-products as animal feed. Without an adequate supply of these feed ingredients, the EU’s livestock production will loose competitiveness. However, demands from the EU differ to those from third countries with respect to the GM varieties grown, and what are authorised for import into the EU. The risk that supplies of soya products and maize by-products could be affected by the low-level presence of non-EU approved GM material has not been fully resolved as the EU has allowed just a 0.1% tolerance for this plus 0.05% tolerance for measuring uncertainty. This could cause supply problems for the animal feed industry, and ultimately supply of food to consumers. The importance of the EU market and EU requirements for the major soybean and maize exporter countries is declining over time and it is becoming increasingly difficult and costly to maintain a non-GM supply chain in the EU. Food companies and supermarkets will struggle to stay GM-free. EU member states dependent on imports will be forced to deal with more GM presence in their chain. Market forces are forcing governments to authorize products more efficiently, develop tolerance policies or tolerate unapproved varieties in their imports.
文摘This paper proposes optimization models of crude oil distillation column for both limited and unlimited feed stock and market value of known products prices. The feed to the crude distillation column was assumed to be crude oil containing naphtha gas, kerosene, petrol and diesel as the light-light key, light key, heavy key and heavy-heavy key respectively. The models determined maximum concentrations of heavy key in the distillate and light key in the bottom for limited feed stock and market condition. Both were impurities in their respective positions of the column. The limiting constraints were sales specification concentration of light key in the distillate [ ], heavy key in the bottom [ ] and an operating loading constraint of flooding above the feed tray. For unlimited feed stock and market condition, the optimization models determined the optimum separation [ and ] and feed flow rate that would give maximum profit with minimum purity sales specification constraints of light key in the distillate and heavy key in the bottom as stated above. The feed loading was limited by the reboiler capacity. However, there is need to simulate the optimization models for an existing crude oil distillation column of a refinery in order to validate the models.
