[F.2]project問題

Luigi996

可唔可以幫我唸吓:
生物能源如何提高生質素
盡快thx,小弟感激不盡

生物能源基本資料:
生物能源
生物能源，或生物質能是利用植物等有機物質作為燃料，通過氣體收集、氣化、燃燒和消化作用等技術產生能源。只要適當地利用，生物能源也是一種寶貴的可再生能源，但也要視乎生物燃料是如何產生出來。

一些潛在生物能源包括：
甲烷氣(包括來自垃圾掩埋場和污水處理廠)
濕潤廢物(例如公共屠宰場、飼育場和食品加工廠)
乾的農業副產品(例如玉米和蔗糖棄渣)
城市廢物(例如家居垃圾和植物籬枝)
林業副產品(例如鋸木廠和林業運作的殘渣)

生物能源的優點
生物能源的最大優點是，只要適當地處理是不會排放溫室氣體。即使燃燒生物燃料會排放二氧化碳，由於種植新的生物燃料時會重新吸收，對氣候影響輕微。也有一些情況，溫室氣體可以在排放前被罩住和利用。例如，當垃圾掩埋場的有機廢物分解，便會釋出比二氧化碳更強的溫室氣體－－甲烷氣。留住甲烷氣並用作燃料，可以避免氣體進入大氣層，並從廢物產生電力。

生物能源的問題
生物能源的最大問題是把食物當作燃料，影響全球糧食供應穩定。我們必須立即停止這種做法。現時，歐美各國定立了強制性生物燃料的發展目標，使肥沃的土地不再種植糧食，導致糧食供應緊張，及糧食價格不斷上漲。而窮國人民無法負擔，便會發生飢餓。

2007年，美國把5400萬噸玉米用於生產乙醇，而歐盟也把285萬公頃土地改種菜籽油和其他作物，生產生物燃料。如果同樣的土地用於種植食用玉米和小麥，估計可生產6800萬噸糧食，足夠供應28個非洲最不發達國家人口一年的糧食。相反，中國於2006年禁止玉米、小麥和稻米等主糧用作生物燃料，成為是全球唯一實施相關禁制措施的國家。

此外，生物燃料也可能造成環境污染。例如，焚燒城市廢物產生能源，可產生二噁英等有毒物質，更會影響循環再造工業的發展。更甚者，有企業試圖破壞原始森林，種植生物燃料。綠色和平反對此舉，因為只會助長砍伐更多珍貴的原始森林。

總言之，開發生物能源時必須避免以下情況，才可真正達致可持續發展：
把糧食作為生物燃料，影響糧食供應及價格
破壞原始森林
產生二噁英等有毒物質
使用基因改造生物
大量使用化肥和農藥
表土流失
鹼性的增加和有毒物質排放

Bioenergy
Bio-energy, or biomass energy is the use of plant and other organic material as fuel, through the gas collection, gasification, combustion and digestion technologies for energy generation. As long as the proper use of bio-energy is also a valuable renewable energy, but it will depend on how the bio-fuel is out.

Some of the potential bio-energy include:
Methane gas (including those from landfills and sewage treatment plants)
Moist waste (such as public abattoirs, feedlots and food processing plants)
Dry agricultural by-products (such as maize and sugar Spoil)
Municipal waste (such as household garbage and hedgerow branches)
Forestry by-products (such as sawmills and forestry operations residues)

The advantages of bio-energy
The biggest advantage of bioenergy is that as long as the proper treatment is not emit greenhouse gases. Even if the burning of biomass fuels emit carbon dioxide, due to cultivation of new bio-fuels will be re-absorbed little impact on the climate. There are also some situations in emissions of greenhouse gases and the use of pre-masked. For example, when landfill decomposition of organic waste, it will release more greenhouse gas than carbon dioxide - methane. To keep methane gas and used as fuel, can be avoided gases into the atmosphere, and from the waste to produce electricity.

Bio-energy issues
The biggest problem with bio-energy is to food as fuel, affecting the global food supply. We must immediately stop this practice. At present, the United States and Europe to set a mandatory bio-fuel development goals, so that is no longer fertile land to grow food, leading to food shortages and rising food prices. The poor people can not afford will be prone to starvation.

In 2007, the United States 54 million tons of corn to produce ethanol, while the EU also put 2.85 million hectares of land switching to rapeseed and other crops, producing bio-fuels. If the same land for growing corn and wheat consumption is estimated to produce 68 million tons of grain, enough to supply 28 African least developed countries, the population of grain a year. On the contrary, China in 2006 to prohibit corn, wheat and rice as a staple food biofuels, as is the only national implementation of the relevant prohibitions.

In addition, bio-fuels can also cause environmental pollution. For example, the burning of municipal waste generated energy, can produce dioxin and other toxic substances, it will affect the recycling industry. What is more, there are companies trying to destroy forests to plant biofuels. Greenpeace opposed the move because it would only encourage the cutting of more valuable forests.

In short, the development of bio-energy when the following conditions must be avoided in order to really achieve the objective of sustainable development:
The food as biofuels impact on food supply and prices
Destruction of forests
Produce dioxins and other toxic substances
The use of genetically modified organisms
Heavy use of fertilizers and pesticides
Topsoil loss
Alkaline growth and emissions of toxic substances