Secretary General of the Belgian Alliance for Sustainable Palm Oil. He used to co-chair the European Sustainable Palm Oil Advocacy Group which brings together five sectors around EU Regulatory issues relevant to the palm oil industry.

As EU Policy Manager he was responsible for the coordination and representation of the margarine sector where he coordinated the industry position for modernisation of legislation and follow up of dietary guidelines (on Belgian Level) and for sustainability and contaminants. Achievements include the development of a sector sustainability guide and improved visibility of the network in the EU Institutions, which lead to a dialogue around the EU policies against deforestation.

Jelmen also was a Board Member of the European Network of Political Foundations for 10 years.

Jelmen also worked in South-Africa and in Israel/Palestine. In South-Africa he coordinated a project with industry, trade unions, and NGOs on HIV/AIDS which lead to a global project in ports and major transport hubs. In Israel/Palestine he acted as a match-maker between mayors, ngo's, and social partners from Israel and Palestine. The network strategy he developped has led to first contacts between Mayors during the intifada and to a new export corridor for agricultural products in the north of the West-Bank.

Jelmen has several academic degrees (a o Executive Master International Association Management, Subsequent Master Banking and Finance, Master Educational Sciences).